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Related papers: Diffusivity in force-free simulations of global ma…

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In this work, eddy diffusivity is derived from the energy spectra for the stable and convective regimes in the planetary boundary layer. The energy spectra are obtained from a spectral model for the inertial subrange that considers the…

Atmospheric and Oceanic Physics · Physics 2024-08-20 A. Goulart , J. M. S. Suarez , M. J. Lazo , J. C. Marques

MHD waves can be responsible for plasma fluctuations and short-term variations of the pulsar emission. We consider the properties of plane and cylindrical waves that can exist in the force-free magnetosphere. Waves are considered by means…

Solar and Stellar Astrophysics · Physics 2015-06-03 V. Urpin

We use the high sensitivity to magnetic flux of mesoscopic conductance fluctuations in large quantum dots to investigate changes in the two-dimensional electron dispersion caused by an in-plane magnetic field. In particular, changes in…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 D. M. Zumbuhl , J. B. Miller , C. M. Marcus , V. I. Fal'ko , T. Jungwirth , J. S. Harris

Convection in the liquid outer core of the Earth is driven by thermal and chemical perturbations. The main purpose of this study is to examine the impact of double-diffusive convection on magnetic field generation by means of 3D global…

Geophysics · Physics 2021-05-12 Théo Tassin , Thomas Gastine , Alexandre Fournier

Electro- and diffusio- phoresis of particles correspond respectively to the transport of particles under electric field and solute concentration gradients. Such interfacial transport phenomena take their origin in a diffuse layer close to…

Soft Condensed Matter · Physics 2020-04-22 Sophie Marbach , Hiroaki Yoshida , Lydéric Bocquet

Electron magnetohydrodynamic (EMHD) turbulence in two dimensions is studied via high-resolution numerical simulations with a normal diffusivity. The resulting energy spectra asymptotically approach a $k^{-5/2}$ law with increasing $R_B$,…

Plasma Physics · Physics 2009-05-01 C. J. Wareing , R. Hollerbach

In this work, the effect of fluctuations in a disordered square lattice on diffusion of a test particle is studied using kinetic Monte Carlo simulations. Diffusion is relevant to a wide variety of problems, both within physics and outside…

Statistical Mechanics · Physics 2016-04-15 Robbert-Jan Dikken , Casper D. Versteylen

Global magnetohydrodynamic (MHD) instabilities are investigated in a computationally tractable two-dimensional model of the solar tachocline. The model's differential rotation yields stability in the absence of a magnetic field, but if a…

Plasma Physics · Physics 2019-02-19 Abigail Plummer , J. B. Marston , S. M. Tobias

We supplement the mean field dynamo growth equation with the total magnetic helicity evolution equation. This provides an explicitly time dependent model for alpha quenching in dynamo theory. For dynamos without shear, this approach…

Astrophysics · Physics 2009-11-07 Eric G. Blackman , Axel Brandenburg

We investigate the diffusive properties of energy fluctuations in a one-dimensional diatomic chain of hard-point particles interacting through a square--well potential. The evolution of initially localized infinitesimal and finite…

Statistical Mechanics · Physics 2009-11-13 L. Delfini , S. Denisov , S. Lepri , R. Livi , P. K. Mohanty , A. Politi

There remains a useful relation between diffusion and mobility for a Langevin particle in a periodic medium subject to nonconservative forces. The usual fluctuation-dissipation relation easily gets modified and the mobility matrix is no…

Statistical Mechanics · Physics 2015-03-17 Marco Baiesi , Christian Maes , Bram Wynants

Some of the most energetic pulsars exhibit rotation-modulated gamma-ray emission in the $0.1$ to $100$ GeV band. The luminosity of this emission is typically $0.1\text{-}10\%$ of the pulsar spin-down power (gamma-ray efficiency), implying…

High Energy Astrophysical Phenomena · Physics 2023-03-20 Hayk Hakobyan , Alexander Philippov , Anatoly Spitkovsky

The evolution of non-potential perturbations to a current-free magnetic X-point configuration is studied, taking into account electron inertial effects as well as resistivity. Electron inertia is shown to have a negligible effect on the…

Astrophysics · Physics 2009-11-10 K. G. McClements , A. Thyagaraja , N. Ben Ayed , L. Fletcher

We derive all contributions to the dispersion measure (DM) of electromagnetic pulses to linear order in cosmological perturbations, including both density fluctuations and relativistic effects. We then use this result to calculate the power…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-30 David Alonso

An oblique pulsar magnetosphere with a plasma conductivity is studied by using a pseudo-spectral method. In the pseudo-spectral method, the time-dependent Maxwell equations are solved, both electric and magnetic fields are expanded in terms…

High Energy Astrophysical Phenomena · Physics 2016-07-27 Gang Cao , Li Zhang , Sineng Sun

A magnetically dominated plasma driven by motions on boundaries at which magnetic field lines are anchored is forced to dissipate the work being done upon it, no matter how small the electrical resistivity. Numerical experiments have…

Astrophysics · Physics 2007-05-23 Aake Nordlund

In view of recent efforts to probe the physical conditions in the pulsar current sheet, we revisit the standard solution that describes the main elements of the ideal force-free pulsar magnetosphere. The simple physical requirement that the…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Ioannis Contopoulos , Konstantinos Kalapotharakos , Demosthenes Kazanas

Close-in terrestrial exoplanets around M dwarfs reside in dense, magnetized winds, where non-ideal plasma coupling can strongly affect how electromagnetic energy is redistributed within the dayside interaction region. We present…

Earth and Planetary Astrophysics · Physics 2026-05-26 J. J. González-Avilés , N. Baltazar Pérez-Negrón , A. Segura

Spherical solar dynamo simulations are performed. Self-consistent, fully compressible magnetohydrodynamic system with a stably stratified layer below the convective envelope is numerically solved with a newly developed simulation code based…

Solar and Stellar Astrophysics · Physics 2015-06-15 Youhei Masada , Kohei Yamada , Akira Kageyama

The effect of compressibility in charged particle energization by magnetohydrodynamic (MHD) fields is studiedin the context of test particle simulations. This problem is relevant to the solar wind and the solar corona due to the…

Plasma Physics · Physics 2016-08-24 C. A. González , P. Dmitruk , P. D. Mininni , W. H. Matthaeus
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